Teat cup cleaning device and method related thereto

ABSTRACT

A teat cup cleaning device having a heating chamber ( 2 ), provided with a discharge ( 3 ) which is closable by a valve ( 4 ), and arranged for connection to a teat cup. A filling device ( 20 ) is provided for filling the heating chamber ( 2 ) with an amount of cleaning liquid ( 11 ), and a heating arrangement is arranged to heat the contents of the heating chamber ( 2 ) to a temperature T higher than the boiling point Tk of the cleaning liquid at ambient pressure. The valve ( 4 ) opens in this situation to deliver the heated cleaning liquid to the teat cup. The teat cup cleaning device also comprising a connecting line ( 17 ) between a liquid supply and the discharge.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from Dutch application number 1033883filed on 24th May 2007 and Dutch application number 1034963 filed on28th Jan. 2008, the contents of both of which are hereby incorporated byreference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general to teat cup cleaning devicesand methods of cleaning teat cups. More particularly, the inventionrelates to teat cup cleaning devices of the type comprising a heatingchamber provided with a discharge outlet closable by means of a valve,and arranged for connection to a teat cup for high temperature cleaning.

2. Description of the Related Art

Document WO03/077645 discloses a device for steam-cleaning of teat cups,comprising a chamber which is closable by means of a pressure valve andwhich contains a heating element. The pressure valve opens at a selectedoverpressure so that a steam jet will be released.

A drawback of the known device is that it is often insufficientlyflexible in use. In particular, it is often slow to heat up and not ableto perform quickly a plurality of cleaning operations successively. Itwould thus be desirable to provide a more flexible and faster operatingcleaning and/or disinfecting device.

BRIEF SUMMARY OF THE INVENTION

The present invention addresses these problems by providing a teat cupcleaning device comprising: a heating chamber, provided with a dischargewhich is closable by means of a valve, and arranged for connection to atleast one teat cup; a filling device for filling the heating chamberwith an amount of cleaning liquid to be heated; a heating arrangement,arranged to heat the contents of the heating chamber to a temperature Thigher than the boiling point Tk of the cleaning liquid at ambientpressure; and a connecting line between a liquid supply and thedischarge. According to the invention, the device may thus comprise adirect connection, or a connecting line, between a liquid supply and thedischarge. This offers the advantage that it is then possible for thedevice to direct, for example, cool liquid to the discharge, for examplefor the purpose of cooling a teat cup after the latter has been cleanedwith hot cleaning liquid, without this cool liquid cooling the heatingchamber. Cooling the heating chamber is generally not necessary and onlywastes energy. Moreover, an additional important advantage is that thedevice is able to heat another amount of liquid in the heating chamberduring the time taken for rinsing. The device will thus be able toperform more quickly successive cleaning and disinfecting actions. Forexample, a single device is thus able to treat smoothly four teat cupsof a milking implement. It is pointed out that the connecting line isable to lead liquid around the heating chamber, that is to say is ableto control the liquid supply to the discharge, circumventing orbypassing the heating chamber. Of course, it is not necessary for theconnecting line to extend physically around the heating chamber. It isdesirable for the connecting line to have a liquid supply which isindependent of the heating chamber and which is connected to thedischarge from the heating chamber, so that there is a common dischargeto one outflow aperture. The connecting line may therefore be aconnecting line of the heating chamber, so that it is connected at oneside to a supply to the heating chamber, and at the other side to thedischarge from the heating chamber, or may also be a connection betweena separate supply, for example directly from a water line or storagevessel, and the discharge from the heating chamber. The directconnection may, for example, comprise a separate line which isadvantageously closable. The liquid may in this case be constituted by aseparate cooling liquid, such as (mains) water, or a non-heated cleaningliquid, etc. In fact there may thus be created a separate circuit.

Alternatively, there is provided a direct connection between the fillingdevice and the discharge which has itself a branch to the heatingchamber, for example via an aperture which is advantageously closable bymeans of a valve or the like. This means that the heating chamber can befilled with new cleaning liquid via that aperture, and optionally viathe valve, during, or better prior to, cooling a teat cup and the like.Such a valve may, again advantageously, be the same as the controllablevalve which is capable of closing the discharge.

If desired, the valve may have a floating action which is advantageouslyadjustable in height. If the heating chamber has been filledsufficiently, the floating valve will close the heating chamber, and itwill be possible to use the remaining liquid for cooling purposes. Itwill be obvious that, in this case, the liquid will comprisesubstantially cleaning liquid.

In a device according to one aspect of the invention, the heatingchamber advantageously comprises an expansion arrangement which isarranged to enable expansion of the liquid to be heated. This ensuresthat there will remain a space for vapor to be formed, but in particularalso for expansion of the liquid to be heated. For example, when wateris heated from room temperature to 100° C., it will expand byapproximately 4% at ambient pressure. This is of course also possiblewithout an expansion arrangement being provided but in that case liquidwill leak along the valve or via other paths, which may sometimes beundesirable.

Advantageously, the expansion arrangement comprises a gas retainingdevice which is arranged to keep a sub-volume of the heating chamberfree of cleaning liquid during filling. Such a gas retaining deviceprovides a “gas bubble” which can control the expansion in a very simplemanner. In this case, attention should be taken that the gas bubble isactually present. This may, for example, be ensured by not tilting thedevice, or by stabilizing the gas bubble by means of hairs, a piece ofgauze, etc.

It is also possible to provide an elastic or displaceable portion, suchas a flexible diaphragm or a displaceable piston. This offers a greatadvantage because the heating chamber can be filled to 100%.

In particular, in the case of unheated cleaning liquid, the sub-volumeamounts to at least 2%, preferably to at least 5%, of the volume of theheating chamber. Taking the expansion of the water and the pressure tobe reached in the heating chamber into account, it proves to besufficient to ensure such a liquid-free volume. The sub-volume amountsto 50% at the most, preferably to 20% at the most, more preferably to10% at the most, of the volume of the heating chamber. By setting amaximum to the sub-volume, it is prevented that too little liquid canget into the heating chamber.

The expansion arrangement comprises, for example, a recess in theheating chamber. In this case, the recess can retain, in the manner of adiving bell, a gas bubble of the desired dimensions. It is possiblethat, in this case, the device should assume a specific position, inparticular in such a way that the aperture of the recess is orientateddownward, but in very many cases the device will have a fixedorientation during use. In particular, the valve for closing the heatingchamber comprises such a recess. In particular, if the valve is directlyconnected to the discharge, it is possible to ensure in a simple mannerthat, after each use (opening) of the valve, the recess will be filledor will continue to be filled with the correct amount of gas.

In a favorable embodiment, the expansion arrangement comprises acompressible element, in particular a movable piston or a closed gasvolume. The expansion may thus be ensured in a very reliable manner. Inthis case, the mobility or compressibility ensures the possibility ofexpansion of the liquid.

The closed gas volume comprises advantageously a volume closed by meansof a diaphragm or piston, in particular a chamber. Such a volume may,for example, be provided in the form of a balloon or the like, which, inthis case, may, for example, be placed in a recess in the heatingchamber. Advantageously, a movable and sealing piston may be provided ina recess. At the closed side, the piston may meet a counter-pressurewhich is caused by enclosed gas and/or, for example, a springarrangement. In a favorable embodiment, the amount of gas and/or thespring arrangement is adjustable. It is thus possible to providesufficient possibility of expansion in the case of other liquids,filling degrees and or pressures in the heating chamber. For example,the closed volume may comprise a valve, or the spring arrangement maycomprise an adjusting screw or the like.

In the foregoing, the volume of the heating chamber may be defined asthe volume in which the pressure can rise when an amount of liquid isheated. This volume then comprises the portion which is reachable byliquid as well as the sub-volume which remains liquid-free but is stillinfluenced by heating.

Further particularities of the invention may be found in the dependentclaims.

According to the invention, the filling device is arranged to stillcontain an amount of cleaning liquid in the liquid state at the momentof opening the valve of the discharge. The heating means have heated thecontents, that is to say the cleaning liquid, to a temperature above thenormal boiling point Tk of that liquid, in which case also vapor will beformed. By opening that valve, the pressure in the heating chamber willfall to the ambient pressure, in which case, of course, the amount ofvapor present will escape. However, it is more important that thecleaning liquid is a superheated liquid at that lower pressure. It willthen start to boil suddenly and with great force. The vapor bubbleswhich are then formed will carry at least a part of the liquid outside.In fact, not only vapor, but a vapor-liquid mixture is carried outsidethrough the discharge. Also in view of the much higher density ofliquid, the total heat content of the vapor-liquid mixture is muchhigher than the heat content of vapor only, so that also the cleaningand/or disinfecting action will be increased considerably. Theunpublished patent application NL 1033100, the contents of which arehereby incorporated by reference in their entirety, already mentionsthis principle.

It is pointed out that the heating chamber may be filled via thedischarge. It is also possible to provide a separate supply to theheating chamber which should then preferably be closable as well, forexample by means of a valve.

Although the discharge may be arranged for connection to a teat cup, theheating chamber as a whole may also be arranged for connection to theteat cup, in which case the discharge should, of course, be provided insuch a way that it is still possible for the heated contents to reachthe teat cup. The discharge or the heating chamber may, for example,comprise a teat cup gripping means, such as one or more clamps. It ispointed out here that connection should be understood in a wider sense,and comprises the situation that the teat cups are placed in a positionenabling them to be cleaned in an efficient manner by means of thedevice. For example, there may be left some clearance between the teatcup and the teat cup cleaning device. This is in particular the case ifan outer side of the teat cup has to be cleaned, but may also occur uponcleaning the inner side of a teat cup. In the latter case, however, itis advantageous to connect the teat cup in a sealing manner to the teatcup cleaning device. In this case, it may again be advantageous toprovide a discharge of contents of the teat cup, such as by means of amilk vacuum connection.

In addition, it is in particular possible to arrange the discharge orthe entire heating chamber for connection to and cleaning of a pluralityof teat cups, such as four teat cups for cows, for example by providinga corresponding number of teat cup gripping means, and/or by dividingthe discharge into a corresponding number of separate sub-discharges. Anembodiment arranged in such a way may save time during cleaning, but mayrequire a higher total power.

The heating arrangement may comprise in principle any known heatingarrangement. Examples are burners, immersion heaters or other electricheating means, microwave radiators, etc. In practice, electric heatingmeans will often be preferred because of their user-friendliness andhigh efficiency.

In particular, the filling device is arranged to fill the heatingchamber with such an amount of cleaning liquid that in the mentionedsituation at least 50%, more preferably at least 90%, of the amount ofcleaning liquid initially supplied in the heating chamber, will bepresent in the liquid state in the heating chamber. It should be notedthat this means that the filling device will try to bring the mentionedamount of liquid into the heating chamber, while in the embodimentshaving a gas retaining means the latter will try to keep the associatedsub-volume free of liquid. In the case of embodiments having an elasticor displaceable expansion device, this is not necessary and a fillingdegree of at most 100% may be applied.

It will be obvious that a higher percentage of cleaning liquid stillpresent in the liquid state will also ensure a higher total heatcontent. The degree of filling of the heating chamber being adjustablewill also make it possible to set the amount of vapor-liquid mixturesupplied, and thus the total heat content thereof. The device may thusbe adapted to different cleaning requirements.

In a special embodiment, the temperature T amounts to at least 130° C.,preferably to at least 160° C., and more preferably to at least 180° C.At a higher temperature, not only the heat content will be greater, butalso the (equilibrium) vapor pressure will be higher and, as a resultthereof, the difference from the ambient pressure will be greater. Uponopening of the heating chamber, that greater pressure difference willalso lead to more violent boiling, so that the contents of the heatingchamber will, moreover, be emitted in a more violent manner. The desiredtemperature will depend on a number of things. The object of the heatingmay be, for example, that the emitted vapor-liquid mixture performs thedesired cleaning and/or disinfection. For this purpose, there is neededa particular heat content which may depend on the teat cup to becleaned/disinfected, the cleaning liquid, the amount and temperaturethereof, etc. Based on an average teat cup, however, a properdisinfection appears to be possible by means of an amount of water,provided or not provided with additives, of at least 50 ml. For example,by means of an amount of water of 80 ml which has been heated toapproximately 185° C. and consequently an associated pressure ofapproximately 8 bar, a teat cup can be disinfected sufficiently. In thiscase, 2 ml to 4 ml of liquid-free volume appears to be sufficient for aproper action. An amount of water of approximately 50 ml may, forexample, be heated to approximately 200° C.-220° C., with an associatedpressure of 16-22 bar. It should be noted that, in the case of suchsmall volumes of vapor, the limits on the basis of regulations from therelevant Steam Vessel Inspectorate may not apply, or at least to alimited extent.

In particular, the valve comprises a pressure-relief valve. This is asimple type of valve which is arranged to open at a particular pressure,for example independently of the type of cleaning liquid. In fact, thedifference from the ambient pressure is relevant, but the latter willvary not more than 2-3%.

An opening overpressure OD of the pressure-relief valve may amount to atleast 2 bar absolute pressure. At this value there is already obtained asatisfactory cleaning action. The opening overpressure OD preferablyamounts to at least 8 bar absolute pressure, for example 8-12 barabsolute pressure. At such values, there is achieved, in most cases, avery good cleaning and also a very good disinfection. It is pointed outthat the mentioned overpressures are to a certain extent connected withthe amount of cleaning liquid which is heated in the heating chamber. Asmall amount will have to be heated to a higher pressure in order tohave sufficient heat content. In practice, overpressure and amount maybe adapted to each other. For example, an (unheated) amount of water of60-80 ml at 8 bar, i.e. approximately 184° C., provides an excellentdisinfecting action in the case of an average teat cup. It is alsopossible, for example, to use 50 ml, at a pressure of for example atleast 16 bar absolute pressure, i.e. a temperature of approximately 200°C.

In one embodiment, the valve comprises a valve which is controllable bymeans of a control device. This provides the possibility of adapting theconditions in which the valve opens to the cleaning wishes in a verysimple manner. For example, if a teat cup is contaminated to a greatextent, or should be disinfected, more heat content is needed than inthe case of teat cups which are not or hardly contaminated. In thatcase, it is not only possible to adapt the amount of cleaning liquid,but also the heating condition. In particular, the flow passage isadjustable. As a result thereof, it is possible to control, and inparticular to prolong, to some extent the period of time in which thevapor-liquid pressure exits. This enables an even better control of thecleaning and disinfection.

In particular, the control device is arranged to open the valve at oneof a temperature OT or a pressure OD, preferably an adjustabletemperature OT or an adjustable pressure OD, in the heating chamber. Theheat content of the cleaning liquid to be emitted can thus be controlledin a very flexible manner.

In a special embodiment, the milking implement comprises a cleaningliquid storage container which is connectable to the heating chamber,preferably by means of a second valve. The milking implement may thus beself-supporting, which may be of great advantage, for example in thecase of an independent or even a self-propelled milking implement. Thecleaning liquid storage container may, for example, comprise a tank,such as, for example, in the form of a boiler known per se. There mayalso be provided a plurality of storage containers, each containing adesired cleaning liquid, in which case the term “cleaning liquid” alsocomprises (for example liquid) “disinfecting agents” in the context ofthis invention. A storage container also provides the possibility ofperforming a pre-treatment on the cleaning liquid, such as pre-heating.However, it is also possible, of course, not to provide a storagecontainer, but to make in each case, according to one's needs, forexample by means of a hose, a connection to an external storagecontainer, such as, for example, a water supply pipe or the like.

In all such cases it is possible for the filling device to fill theheating chamber with a measured amount of cleaning liquid. For thispurpose, the storage container may, for example, be disposed over theheating chamber, so that the gravitational force will act as drivingforce. Alternatively, a pumping means or the like may be provided in thestorage container, or in an external storage container. The fillingdevice may also comprise a controllable valve or be arranged to controlthe valve of the heating chamber. In order to determine the amount, thefilling device may be equipped, for example, with a flow meter, with afilling chamber having a preferably adjustable volume, or with any otherauxiliary means known in the state of the start and suitable for thepurpose.

In one embodiment, the cleaning liquid comprises water, in particularsubstantially water. Water constitutes a very useful cleaning anddisinfecting liquid because of its very great heat content, itssufficiently high temperature as a vapor and its great availability inits pure form at a low price. However, other cleaning liquids oradditives are not excluded.

In particular, the cleaning liquid comprises a disinfecting agent, forexample an acid. Addition of a disinfecting agent may still reinforcethe disinfecting action. In special cases, the cleaning liquid comprisessubstantially the disinfecting agent, in particular if the latter isliquid and can be supplied as vapour.

The heating means have advantageously an adjustable heating power. Thisadjustability may be switched on and off in a simple manner, but theeffective heating power is advantageously adjustable into two or moredifferent positions with heating power unequal to zero, and is moreadvantageously continuously adjustable. This may, for example, provideadvantages if the amount of cleaning liquid to be heated varies. For,heating a small amount is better controllable with a small heatingpower.

In particular, the heating arrangement comprise a control device whichis arranged to control the heating arrangement in such a way that thementioned situation is not reached, in order to keep the valve closed,at least the valve which closes the discharge. This means that theheating arrangement controls the heating condition of the contents ofthe heating chamber in such a way that the condition in which the valveof the discharge would open is not reached, that is to say that thepressure in the heating chamber remains below the opening overpressureOD, or a corresponding temperature in the heating chamber is kept belowthe temperature T, the equilibrium vapor pressure being equal to OD,etc. This provides the advantage that the teat cup cleaning device isalways ready for cleaning a teat cup (almost) immediately, as soon asthe latter is connected, at any rate is offered for cleaning. Thesecontrol means may moreover be integrated in other control means, if any,such as control means for controlling the valve (in the discharge).

In certain embodiments, the control means are arranged to switch on theheating means during a desired period of time. Preferably, the desiredperiod of time is adjustable, for example in dependence on the amount orsort of cleaning liquid to be heated, or the desired temperature. Ifdesired, the control means may, advantageously, moreover be arranged toopen subsequently the controllable valve. As the effective power of theheating arrangement may vary, for example by (mains) voltagefluctuations in the case of electric heating means, there isadvantageously provided a power correcting device which is connected tothe heating arrangement. The power correcting device comprises, forexample, a power stabilizer, such as a voltage corrector, or an energymeter.

Advantageously, the discharge comprises a discharge duct projecting overa distance L beyond the wall, in particular the wall of the heatingchamber, wherein L is equal to at most the internal depth of the teatcup to be cleaned. By means of such a discharge duct it is possible toclean the interior of the teat cup in a particularly efficient manner.In that case, the discharge duct comprises, of course, at least oneaperture, for example at its end, but preferably one or more aperturesin a side wall thereof. Such an embodiment is, of course, also suitablefor cleaning the exterior of the teat cup.

Other embodiments of the discharge are possible as well. For example,the invention also provides a device wherein the discharge comprises aclosable aperture in a wall of the heating chamber. In this case, theteat cup may be disposed against that wall around the aperture of thedischarge. An additional advantage may be that the upper side of theteat cup will also be disinfected at least to some extent by means ofcontact with the (hot) wall.

In a particular teat cup cleaning device according to the invention, thevalve is controllable by a teat cup to be cleaned. For this purpose thedevice comprises, for example, an opening mechanism, in the form of aspring mechanism, a push button, a sensor or the like. It is alsopossible to provide a separate control mechanism, such as a manualcontrol mechanism.

The invention also provides a method of cleaning a teat cup by means ofe.g. a teat cup cleaning device as described above, comprising supplyingan amount of cleaning liquid in a heating chamber which comprises adischarge which is closable by means of a valve, and which is arrangedfor connection to a teat cup, closing the heating chamber by means ofthe valve, heating the cleaning liquid in the heating chamber to acondition with a temperature T which is higher than a boiling point Tkof the cleaning liquid at ambient pressure, opening the valve at thiscondition, leading the heated contents of the heating chamber via thedischarge into a teat cup, and supplying rinsing liquid via thedischarge to rinse the teat cup, whereby the rinsing liquid is arrangedto bypass the heating chamber. The method substantially corresponds tothe application of the device described above and therefore theadvantages of the method will not be set out again in further detail.However, it is pointed out that for applying the method it is notnecessary to provide a filling device. It is thus also possible, forexample, to fill an amount of cleaning liquid manually. In particular,it is advantageous if rinsing liquid is led to the teat cup via theconnecting line and the discharge during the heating step. In this case,the heating step should be considered as the period in which the heatingchamber is closed and at least a partial heating of the liquid presenttherein has taken place. For, in that case, there is in particular anenergetic and/or time advantage in relation to systems and methods inwhich liquid is (continuously) led through the heating chamber. For,according to the invention, it is indeed possible to lead unheatedliquid separately outside during heating or to keep liquid in a heatedcondition in the heating chamber.

Particular embodiments of this aspect of the method of the invention aredescribed in the dependent claims. Again, the advantages substantiallycorrespond to the related particular embodiments of the device accordingto the invention and these will, for the sake of brevity, not be set outagain in further detail.

In particular, the amount of cleaning liquid is chosen in such a waythat, when the valve opens, at least 50%, more preferably at least 90%,of the amount of cleaning liquid initially supplied in the heatingchamber is still present in the liquid state in the heating chamber.

Preferably, the cleaning liquid comprises water, and/or the cleaningliquid comprises a disinfecting agent, for example an acid.

In particular, the valve opens at an adjustable threshold value of aparameter. By means of this the opening characteristic can be chosen inan efficient manner, so that the cleaning characteristic can be chosenas well. The parameter may be chosen from many suitable parameters, ofwhich some favorable examples will be provided below.

In embodiments of the method, it is advantageous to cool a teat cup,which teat cup has been cleaned by means of hot cleaning liquid, bymeans of a liquid which is also supplied via the discharge, or, ifdesired, via a separate discharge. In particular when using a devicehaving a connecting line for liquid supply, this may take place in onego, in which case as little heat as possible, in particular of the stillhot heating chamber, will be lost.

In embodiments of the method, the heating chamber is cleaned by fillingit with a cleaning liquid and, if desired, by keeping the liquid in theheating chamber during a predetermined period of time, in order toenable a profound cleaning action, and by subsequently discharging theliquid via the discharge. The latter may take place advantageously byheating also this liquid to above its boiling point at ambient pressure.The liquid will then be removed, again in the case of opening thedischarge, by means of a vapor jet.

In a special embodiment, the threshold value is an overpressure OD inthe heating chamber and, as the threshold value OD, at least 2 bar aboveambient pressure, preferably at least 8 bar absolute pressure, is set.

In another special embodiment, the threshold value is a temperature OTin the heating chamber and, as the threshold value OT, at least 130° C.,preferably at least 160° C., and more preferably at least 180° C., isset.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained hereinafter in further detail withreference to the drawing, in which some non-limiting exemplaryembodiments are shown, and in which:

FIG. 1 shows a diagrammatic cross-section of a device according to theinvention;

FIG. 2 shows a diagrammatic cross-section of a part of an alternativeembodiment;

FIG. 3 shows a diagrammatic cross-section of another alternativeembodiment;

FIG. 4 shows a diagrammatic cross-section of an embodiment with a gasretaining means, and

FIG. 5 shows a diagrammatic cross-section of another embodiment withother expansion means.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The following is a description of certain embodiments of the invention,given by way of example only and with reference to the drawings. In FIG.1, the device 1 comprises a heating chamber 2 with a discharge 3 whichis closable by means of a valve 4. A valve controlling mechanism 5 isconnected to the control unit 6 which is connected in turn to a heatingcoil 7, a thermometer 8 and a proximity sensor 10 in a sealing rim 9.

An amount of cleaning liquid is denoted by 1 1, and an amount of vaporby 12. A discharge nozzle is denoted by 13 and has apertures 14. A teatcup is denoted by 15 and has a milk discharge 16. A connecting line isdenoted by 17, and a control valve by 18. A filling device is denoted by20 and comprises a supply line 21 and a valve/pump 22. There is furthershown a storage container 23 with a cleaning liquid stock 24 and animmersion heater 25.

The heating chamber 2 may be made of thermally insulating material or besurrounded thereby. Furthermore, the chamber 2 should be able to resista certain internal pressure and temperature, for which reason it oftenalso comprises a metal housing.

The discharge 3 is closable by means of a valve 4 which is preferablycontrollable, for example by means of an optional valve controlmechanism 5 which may be set, for example, manually or, as shown, bymeans of a control unit 6. This means that the pressure at which thevalve 4 opens is adjustable. Furthermore, the passage, and thus the exitvelocity, of vapor and/or liquid may be adjustable. The controlmechanism may comprise an adjustable spring or be electronicallycontrolled, etc.

The pressure is built up by heating an amount of cleaning liquid 11,often water, by means of a heating coil 7. The heating coil 7 may alsobe disposed around the heating chamber 2, or in a wall thereof. Otherheating means, such as microwave heating etc., may also be applied. Thepower of the heating coil or the like should be sufficient to bring thecontents of the heating chamber 2 to the desired pressure and/ortemperature. In practice, values of 160° C. to 180° C. are oftendesired, at an amount of approximately 80 to 100 cm³. An effective poweris then, for example, some hundreds of Watts, although in principle anyother power which is greater than the thermal loss at the desiredtemperature may be suitable as well.

A thermometer 8 may give feedback regarding the temperature to thecontrol unit 6, both of which are optional. The control unit 6 may, forexample, control the heating by means of the coil 7 on the basis of ameasured temperature. 8 might also be a pressure sensor, which, however,should then preferably be disposed in the part of the vapor 12.

For sealing connection of a teat cup 15 there is provided, for example,a sealing rim 9. The latter comprises, for example, a proximity sensor10 which supplies a signal to the control unit 6 when a teat cup 15 hasbeen connected. At the receipt of such a signal the control unit 6 mayorder the filling of the heating chamber 2, to start the heating, or toopen the valve 4. Incidentally, when the teat cup 15 is beingpositioned, the discharge nozzle 13 will be brought into the teat cup.When the valve 4 opens, the superheated contents will get into the teatcup 15 via the discharge nozzle 13 and through the apertures 14, whichensures an excellent local cleaning or disinfection. A possibleoverpressure within the teat cup 15 may be discharged in a simple mannervia the milk discharge 16, the latter being already provided in the teatcup. The proximity sensor is optional, and the function may also beassumed by the valve 4 itself. For example, the latter may be designedin such a way that it only opens if a teat cup 15 is pressed against itwith sufficient force. This is then also a protection against undesiredopening of the valve 4.

It is visible in FIG. 1 that the heating chamber 2 is filled for morethan 90% with cleaning liquid 11, and with vapor 12 above the liquid. Inpractice, this offers a favorable amount of heat for the total contentsof the heating chamber 2. It is already sufficient per se if, at themoment when the desired temperature/overpressure is reached, cleaningliquid in the liquid state is still present. The corresponding amount ofliquid which should be supplied initially may be calculated in advance,or, for example, be determined by experiment.

Supplying the desired amount of cleaning liquid 11 takes place, forexample, manually, or by means of a filling device 20. The lattercomprises at least a supply line 21 for filling the heating chamber,which supply line is connectable to a storage container 23, as well as avalve/pump 22. The latter may perform a pumping action if there isinsufficient pressure action from the storage container 23. In case ofsufficient pressure, a valve will suffice, which valve is controllable,for example, by means of a control device 6. By means of the controldevice 6 it is then possible to determine in a simple manner how muchcleaning liquid is supplied in the heating chamber. Moreover, it ispossible to choose from different cleaning liquids, or, for example,additives, such as disinfecting substances, if, for example, a pluralityof storage containers are provided (not shown). In order to facilitatethe filling of the heating chamber, there may be provided an air-reliefvalve (not shown). The cleaning liquid stock 24 may already have beenpre-heated by means of the immersion heater 25 or the like, so that arelevant amount in the heating chamber 2 will sooner be at the desiredtemperature.

There is also shown a connecting line 17 which constitutes a directconnection between the storage container 23, thus in general a liquidsupply, and the discharge 3. The connecting line is controllable bymeans of a control valve 18. Liquid can thus be led to the discharge,for example in order to rinse or cool a teat cup, without having to flowthrough the hot heating chamber. This provides energetic advantagesbecause the heating chamber itself is not cooled, but also enablesrinsing/cooling at simultaneous heating of a (new) amount of liquid. Asa result thereof the device is sooner ready for a next cleaning ordisinfection.

FIG. 2 is a diagrammatic cross-sectional view of a part of analternative embodiment. Similar components are denoted here, like in therest of the drawing, by the same reference numerals. Some components,such as heating means and the connecting line, have been omitted herefor the sake of clarity.

In FIG. 2, the heating chamber 2 comprises an overflow tube 26 with aduct 27. The heating chamber 2 further comprises a valve 4 which may becontrolled via a valve control 28 and a reset spring 29. A flow meter isdenoted by 30 and a level meter by 31.

The overflow tube 26 serves, on the one hand, to discharge thesteam-cleaning liquid mixture, via the duct 27, and, on the other hand,subsequently to refill the heating chamber 2. For, if the chamber 2 isempty, cleaning liquid will be supplied again via the supply line 21,for example under the influence of gravitational force in a storagevessel or the like positioned at a higher level. This filling maycontinue until the level of the liquid 11 reaches the top of theoverflow tube 26. In case of further supply, the cleaning liquid 11 willescape via the duct 27. This liquid may, for example, be used forpost-rinsing and/or for cooling the cleaned teat cup 15.

The level is adjustable by choosing the (relative) height of theoverflow tube 26. By moreover choosing the tube 26 as a small one, thenot fillable portion may be very small, but yet sufficiently large toenable expansion of the liquid when the latter is heated. In this case,the overflow tube 26 may serve, if desired together with the depictedspace above valve 4, as gas retaining means.

Stopping the supply may take place under the action of a flow meter 30in the supply line 21. There may also be used a level meter 31 which maybe designed, for example, as a conductivity meter, a temperature meter,etc.

In a preferred embodiment, the level meter 31 may be disposed at theouter side of the heating chamber 2, for example as a temperature meter,so that it is less or not hindered by calcium deposit, steam erosion andthe like. Moreover, it is pointed out here that in fact the entireheating chamber may be free of electrically or electronically controlledvalves and the like, as will be set out hereinafter in further detail.

The valve 4 is not only a safety valve which opens when the pressure inthe chamber 2 becomes too high for any reason whatsoever. Moreover, thisvalve may be controlled by means of a valve control 28 in such a waythat it will open in a desired manner and at a desired point of time.Advantageously, the valve control 28 is controllable by pressing againstit by means of a teat cup 15. It will then be possible for the valve 4to move in the direction of the arrow and to open. The reset spring 29keeps the valve 4 closed in the inoperative position. Other embodimentsof such a valve 4 are conceivable, such as provided with springs,sliding means, levers and the like.

Please note that the time required for cleaning and/or disinfecting theteat cup by means of the hot contents ejected from the heating chambermay be used for refilling the chamber 2. It is also possible, of course,to withdraw the cup 15 from the device during some time. The chamber 2then fills and will not overflow, because the valve 4 is in a closedposition.

FIG. 3 shows a diagrammatic cross-section of another alternativeembodiment. Here, 21 is a supply line for liquid, such as cleaningliquid, which is closable by means of a non-return valve 22′. The supplyline 21 is connected to the discharge nozzle 13 via a connecting line17.

Here, the valve 4 has been brought under pretension by means of a resetspring 29, and may further be operated by means of a pneumatic (oralternatively) hydraulic mechanism which comprises: a pump 32, a gaspassage 33 and a pressure chamber 34. By means of this mechanism it ispossible to operate the valve 4 in a quick and simple manner.

The valve 4 may also be provided in the heating chamber 2, and have inthat case a floating action. By rinsing or cooling the device by meansof liquid, the heating chamber 2 will be filled, in which case the floatvalve will rise until it closes the heating chamber.

As already indicated with reference to FIG. 1, the function of theconnecting line 17 is, in the case of cooling a teat cup by means ofcool liquid flowing through, to prevent this liquid from flowing alsothrough the heating chamber 2 and thus cooling the latter unnecessarily.For this purpose, the heating chamber 2 may be closed by means of thevalve 4. Since, however, the heating chamber should be filled again with(cleaning) liquid, it is, as an alternative, also possible to fill theheating chamber 2 with the rinsing liquid during rinsing/cooling. Assoon as the heating chamber 2 has been filled, either the liquid flowsby itself “across the chamber 2”, or the chamber 2 may be closedactively, such as by means of the valve 4.

FIG. 4 shows a diagrammatic cross-section of an embodiment with a gasretaining means. In this case, the heating chamber 2 comprises anadmission valve 19 with an air chamber 35. The air chamber serves toretain a particular air volume in the chamber 2, such as for example 2ml based on a total volume of 50 ml. The air chamber 35 here comprises arecess in the valve 19. This recess may also be provided in a wall ofthe chamber 2. The valve 19 may be guided in order to prevent tilting,and may, for example, furthermore float on liquid in the chamber, inorder to close the chamber 2 by floating action.

The valve 4 is only shown diagrammatically. The connecting line 17 againconnects a supply line 21 to the discharge 3. A not shown control devicemay be provided in the supply line 2 1.

FIG. 5 shows a diagrammatic cross-section of another embodiment withother expansion means.

A first expansion means is diagrammatically denoted by the referencenumeral 36, and comprises a piston 37 in a cylinder 38, a spring 39, anadjusting screw 40, a gas volume 41, an air connection 42 and a controlvalve 43.

The expansion means 36 serves to enable expansion of liquid to be heatedin the heating chamber 2 without liquid leaking from the discharge(valve), not shown here. When the liquid expands, or simply when thevapor pressure increases, the piston 37 will be pressed into thecylinder 38, against a counter-pressure. This counter-pressure may becaused by a spring 39, but also by an enclosed gas. In the former case,the space in the cylinder 38 behind the piston 37 may in fact beconsidered as belonging to the environment, thus outside the heatingchamber 2, and a filling degree of 100% can be permitted. When there isgas or air in the cylinder, the pressure, both in the chamber 2 and inthe cylinder 38, will increase upon heating. Therefore, the space in thecylinder 38 belongs to the chamber 2, as defined in this context.Therefore, if the cylinder is filled with gas, a minimum space of, forexample, 2% to 5% of the chamber 2 should be taken into account.

The counter-pressure may also be adjustable, for example by operatingthe adjusting screw 40, or by leaving more or less air (gas) in thespace behind the piston 37, by means of the air connection 42 and thecontrol valve 43. Alternatively, the piston-cylinder-combination mayalso be replaced by a flexible diaphragm or the like in a wall of thechamber 2.

Another expansion means is provided in the form of the balloon 44 whichencloses a gas volume 45. In the case of heating and expansion of theliquid it will be possible to compress the balloon 44. The balloonitself may again be enclosed or otherwise fastened in a suitableposition, in which, for example, no supply or discharge is blocked. Suchan embodiment is very reliable, because the expansion means cannotescape from the chamber 2, and can be made leak-tight in a very propermanner, which may be an advantage relative to, for example, pistons incylinders. Moreover, in comparison with the flexible diaphragm, there isa much smaller risk of damage or breakage, which may enhance safety.

The invention is not limited to the embodiments shown. The personskilled in the art will be able to apply various modifications andadaptations without departing from the spirit and scope of theinvention, the scope of protection for the invention being determined bythe accompanying claims.

1. A teat cup cleaning device comprising: a heating chamber, providedwith a discharge which is closable by means of a valve, and arranged forconnection to at least one teat cup; a filling device for filling theheating chamber with an amount of cleaning liquid to be heated; aheating arrangement, arranged to heat the contents of the heatingchamber to a temperature T higher than the boiling point Tk of thecleaning liquid at ambient pressure; and a connecting line between aliquid supply and the discharge.
 2. Teat cup cleaning device accordingto claim 1, wherein the connecting line comprises a separate line,distinct from the filling device.
 3. Teat cup cleaning device accordingto claim 1, wherein the connecting line forms part of the filling deviceand has a branch to the heating chamber via an aperture.
 4. Teat cupcleaning device according to claim 3, wherein the aperture is closableby means of the valve in order to close the discharge.
 5. Teat cupcleaning device according to claim 1, wherein the heating chambercomprises an expansion arrangement, arranged to enable expansion of theliquid to be heated.
 6. Teat cup cleaning device according to claim 5,wherein the expansion arrangement comprises a gas retaining device whichis arranged to keep a sub-volume of the heating chamber free of cleaningliquid during filling, wherein the sub-volume in the case of unheatedcleaning liquid amounts to at least 5%, and at the most 10%, of thevolume of the heating chamber.
 7. Teat cup cleaning device according toclaim 6, wherein the expansion arrangement comprises a recess in theheating chamber.
 8. Teat cup cleaning device according to claim 6,wherein the expansion arrangement comprises a compressible element. 9.Teat cup cleaning device according to claim 6, wherein the compressibleelement comprises a closed gas volume comprising a volume closed bymeans of a diaphragm or piston.
 10. Teat cup cleaning device accordingto claim 1, wherein the filling device is arranged to fill the heatingchamber with such an amount of cleaning liquid that on heating to thetemperature T at least 90%, of the amount of cleaning liquid initiallysupplied in the heating chamber, will be present in the liquid state inthe heating chamber.
 11. Teat cup cleaning device according to claim 1,wherein the temperature T amounts to at least 160° C.
 12. Teat cupcleaning device according to claim 1, wherein the valve comprises apressure-relief valve.
 13. Teat cup cleaning device according to claim12, wherein an opening overpressure OD of the pressure-relief valveamounts to at least 8 bar absolute pressure.
 14. Teat cup cleaningdevice according to claim 1, wherein the valve is controllable by meansof a control device.
 15. Teat cup cleaning device according to claim 14,wherein the control device is arranged to open the valve at one of atemperature OT or a pressure OD, in the heating chamber.
 16. Teat cupcleaning device according to claim 1, wherein the filling devicecomprises a cleaning liquid storage container which is connectable tothe heating chamber.
 17. Teat cup cleaning device according to claim 12,wherein the heating arrangement comprise a control device which isarranged to control the heating arrangement in such a way that thetemperature T is not reached, in order to keep the valve closed. 18.Teat cup cleaning device according to claim 1, wherein the dischargecomprises a discharge duct projecting a distance L beyond a wall of theheating chamber, wherein L is equal to at most an internal depth of ateat cup to be cleaned.
 19. Teat cup cleaning device according to claim1, wherein the valve is controllable by a teat cup to be cleaned.
 20. Amethod of cleaning a teat cup by means of a teat cup cleaning device,comprising: supplying an amount of cleaning liquid to a heating chambercomprising a discharge which is closable by means of a valve, and whichis arranged for connection to a teat cup; closing the heating chamber bymeans of the valve; heating the cleaning liquid in the heating chamberto a condition with a temperature T which is higher than a boiling pointTk of the cleaning liquid at ambient pressure, opening the valve at thetemperature T; leading the heated contents of the heating chamber viathe discharge, into the teat cup; and rinsing the teat cup via thedischarge, with a supply of liquid arranged to bypass the heatingchamber.
 21. Method according to claim 20, wherein rinsing takes placeduring the heating step.
 22. Method according to claim 20, wherein theamount of cleaning liquid is chosen in such a way that, when the valveopens, at least 50% of the amount of cleaning liquid initially suppliedto the heating chamber is still present in the liquid state in theheating chamber.
 23. Method according to claim 20, wherein the cleaningliquid comprises a disinfecting agent.
 24. Method according to claim 20,wherein the valve opens at an adjustable threshold value of a parameter.25. Method according to claim 24, wherein the parameter is anoverpressure in the heating chamber and the threshold value OD is atleast 2 bar above ambient pressure.
 26. Method according to claim 24,wherein the parameter is a temperature in the heating chamber and thethreshold value OT is at least 130° C.
 27. A teat cup cleaning devicecomprising: a pressure retaining heating chamber for receiving aquantity of cleaning liquid; a supply line for supplying cleaning liquidto the heating chamber; a discharge outlet for delivering cleaningliquid from the heating chamber to at least one teat cup; a heatingarrangement, arranged to heat the contents of the heating chamber to atemperature T higher than the boiling point Tk of the cleaning liquid atambient pressure; and a connecting line between the supply line and thedischarge outlet, the connecting line bypassing the heating chamber.